Data commit

Task/Draw-a-sphere/C-sharp/draw-a-sphere.cs

@@ -0,0 +1,51 @@
+using System;
+
+namespace Sphere {
+    internal class Program {
+        private const string Shades = ".:!*oe%&#@";
+        private static readonly double[] Light = {30, 30, -50};
+
+        private static void Normalize(double[] v) {
+            double len = Math.Sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2]);
+            v[0] /= len;
+            v[1] /= len;
+            v[2] /= len;
+        }
+
+        private static double Dot(double[] x, double[] y) {
+            double d = x[0]*y[0] + x[1]*y[1] + x[2]*y[2];
+            return d < 0 ? -d : 0;
+        }
+
+        public static void DrawSphere(double r, double k, double ambient) {
+            var vec = new double[3];
+            for(var i = (int)Math.Floor(-r); i <= (int)Math.Ceiling(r); i++) {
+                double x = i + .5;
+                for(var j = (int)Math.Floor(-2*r); j <= (int)Math.Ceiling(2*r); j++) {
+                    double y = j/2.0 + .5;
+                    if(x*x + y*y <= r*r) {
+                        vec[0] = x;
+                        vec[1] = y;
+                        vec[2] = Math.Sqrt(r*r - x*x - y*y);
+                        Normalize(vec);
+                        double b = Math.Pow(Dot(Light, vec), k) + ambient;
+                        int intensity = (b <= 0)
+                                            ? Shades.Length - 2
+                                            : (int)Math.Max((1 - b)*(Shades.Length - 1), 0);
+                        Console.Write(Shades[intensity]);
+                    }
+                    else
+                        Console.Write(' ');
+                }
+                Console.WriteLine();
+            }
+        }
+
+        private static void Main() {
+            Normalize(Light);
+            DrawSphere(6, 4, .1);
+            DrawSphere(10, 2, .4);
+            Console.ReadKey();
+        }
+    }
+}